1. Field of the Invention
The present invention relates to a vertically fully rotating hook of a sewing machine, and more particularly, to a vertically fully rotating hook which is preferably used in a sewing machine for zigzag sewing and a sewing machine for embroidery sewing.
2. Description of the Related Art
FIG. 1 is an expanded cross sectional view showing a needle location hole 109 and a portion around the same of an inner loop taker 100 according to a conventional technique. A needle thread 101 passes through a thread hole 104 which is formed in the vicinity of a tip portion 108 of a needle 103 which moves up and down reciprocally. When the needle thread 101 is supplied by the needle 103 immediately in front of a blade tip 102, the blade tip 102 catches the needle thread 101 and forms a needle thread loop, so that the needle thread loop is meshed with a bobbin thread not shown and a stitch is formed.
During displacement of the needle 103 downwardly, since cloth which is penetrated by the needle is moved by means of a feeding operation of the sewing machine, the needle 103 may be slightly warped in the direction in which the cloth is moved and contact a flange 105 of the inner loop taker 100. To prevent the contact from breaking the needle 103, a slanted surface 107 is formed in the vicinity of a top portion of the flange 105 to face the needle location hole 109 in the conventional technique.
In the conventional technique described above, the effect of preventing damage to the needle 103 is insufficient. Although there is not a big problem with an ordinary sewing machine in which the direction of feeding a cloth which is sewn is constant, in a zigzag sewing machine or an embroidery sewing machine, the needle 103 collides with the slanted surface 107 when a cloth is fed continuously or even during double fabric sewing of a thick cloth which is fed intermittently. When this occurs, the needle 103 is subjected to great impact, and the great impact breaks the needle 103 or damages the tip portion 108 of the needle 103.
Further, in the conventional technique described above, when the needle 103 is warped while in the needle location hole 109, the needle thread 101 is led out as it is held between a wall 106 and the needle 103. Since the needle thread 101 is formed by twisting a plurality of single threads, contact of the needle thread 101 and the wall 106 damages the single threads, whereby the thread is cut or tangled in the form of a ball.